A Review of Atmospheric Electricity Research in China

The importance of atmospheric electricity research has been increasingly recognized in recent decades. Research on atmospheric electricity has been actively conducted since the 1980 s in China. Lightning physics and its effects, as important branches of atmospheric electricity, have received more attention because of their significance both in scientific research and lightning protection applications. This paper reviews atmospheric electricity research based primarily on ground-based field experiments at different regions in China in the last decade. The results described in this review include physics and effects of lightning, rocket-triggered lightning and its physical processes of discharge, thunderstorm electricity on the Tibetan Plateau and its surrounding areas, lightning activity associated with severe convective storms, the effect and response of lightning to climate change, numerical simulation of thunderstorm electrification and lightning discharge, lightning detection and location techniques, and transient luminous events above thunderstorms.

Case Studies of Sprite-producing and Non-sprite-producing Summer Thunderstorms

Three summer thunderstorms in the eastern region of China were analyzed in detail using multiple data, including Doppler radar, lightning location network, TRMM （Tropical Rainfall Measuring Mission）, MT- SAT （Multi-Function Transport Satellite） images, NCEP （National Centers for Environmental Prediction） Reanalysis, and radiosonde. Two of the three storms were sprite-producing and the other was non-sprite- producing. The two sprite-producing storms occurred on 1 2 August and 2~28 July 2007, producing 16 and one sprite, respectively. The non-sprite-producing storm occurred on 29-30 July 2007. The major ob- jective of the study was to try to find possible differences between sprite-producing and non-sprite producing storms using the multiple datasets. The results showed that the convection in the 1-2 August storm was the strongest compared with the other storms, and it produced the largest number of sprites. Precipitation ice, cloud ice and cloud water content in the convective regions in the 1-2 August storm were larger than in the other two storms, but the opposite was true in the weak convective regions. The storm microphysical prop- erties along lines through parent CG （cloud-to-ground lightning） locations showed no special characteristics related to sprites. The flash rate evolution in the 1-2 August storm provided additional confirmation that major sprite activity coincides with a rapid decrease in the negative CG flash rate. However, the evolution curve of the CG flash rate was erratic in the sprite-producing storm on 27-28 July, which was significantly different from that in the 1 2 August storm. The average positive CG peak current in sprite-producing storms was larger than that in the non-sprite-producing one.

A gigantic jet event observed over a thunderstorm in China's Mainland

Gigantic jet(GJ) is a type of large-scaled transient discharge which occurs above thunderstorms.It connects the thunderstorms and ionosphere directly.Compared with the other transient luminous events(TLEs),gigantic jet is very difficult to be seen from the ground.We report a GJ event that was clearly recorded in eastern China(storm center located at 35.6°N,119.8°E,near the Huanghai Sea) at 20:16:22(local time) on 12 August,2010.It is by far the furthest from the equator ground-based GJ recorded over summer thunderstorm.The top altitude of this GJ was estimated to be about 89 km.The GJ-producing storm was a multi-cell thunderstorm and the GJ event occurred in the storm developing stage,with the lowest cloud-top brightness temperature about 73°C and the maximum radar echo top around 17 km.Altitudes with reflectivity of 45 dBZ were estimated to reach 12-14 km.Different from results from other countries that positive CGs(Cloud-to-ground lightnings) dominated during a time period centered at GJ,our study shows that negative CGs dominated during a time period centered at the GJ event and during most of the storm lifetime in this study,indicating a diversity of the lightning activity in the GJ-producing storms.It is interesting that two different storms produced two types of TLEs,that is,the GJ-producing storm only produced one GJ event during its lifetime and five sprites were produced over another storm,different from the other study that sprites and GJs were usually produced by the same storm,enriched the knowledge of GJ-producing storms.In addition,the GJ event in this study is located beyond the effective coverage area(30°S-30°N) of the ISUAL instruments onboard the FORMOSAT II satellite,and results of this study could be useful for GJ studies in the future.